Bug fixes related to unicode support in export workflow.

[cahrens]

This fixes 2 issues sited in STUD-868:

1. poll_module did not handle unicode characters in the answer text. I modified the toy course so that existing "roundtrip" export tests cover this fix.

2. Fix the logging exception message that is currently breaking UT.2.01x.

@adampalay @singingwolfboy Please review.

@zubair-arbi This bug may also interest you.

[brianhw]

LGTM. 👍

[singingwolfboy]

Huh?

[singingwolfboy]

Oh, this is a test. Never mind.

[cahrens]

Yes, I added it to the existing toy test course so that it covered the bug fix (a unit test fails without the fix).

[cahrens]

@dmitchell Can you review so I can go ahead and merge this? Brian's thumbs-up was on an earlier version.

[dmitchell]

I'm surprised we're grinding the xml out literally rather than using a library like etree. I don't know what different it would make to use a library tho (I'm wondering if it handles the {text} payload better if it has tags and such). (the code would be

  # if self.question is parsable xml
  xml_object = etree.Element(self._tag_name)
  xml_object.append(etree.fromstring(self.question))
  # if self.question is just text
  xml_object = etree.Element(self._tag_name, text=self.question)
  xml_object.set('display_name', self.display_name)
  ...

but that assumes self.question is itself parsable xml. Otherwise

[cahrens]

This is interesting, and I did play around with it. However, it does not appear to be straightforward.

I don't think self.question is necessarily parsable XML (and using the first suggested option leads to a unit test error related to unexpected end of document).

Using text=self.question stores the question as a text attribute, which is different from how it is currently stored. This leads to roundtrip export unit test failures (different failures from the first suggested option).

It does appear that using etree properly handles unicode. Nonetheless, with my very limited understanding of this code, I think that changing how the XML is generated is beyond the scope of this bug fix.

[dmitchell]

That's ok. I can hold my nose and fully agree you're not responsible :-)

As to how to do it, if self.question may sometimes be parsable xml, then surround the fromstring call w/ try/except and do xml_object.set('text', self.question) in the except (I think). BUT, I'm cool w/ leaving it as is (do no harm).

[dmitchell]

If you think the reset, name, and any other original attrs are handled correctly, 👍